Can the order of your birth affect your job?

A first-born or only child may be more likely to become a doctor or lawyer. Younger siblings more often turn to the arts or the outdoors. In part, you can credit parenting.

Parents may over-protect oldests or onlies. So they tend to follow more brain-based interests. When later children show up, parents can be more relaxed and hands-off.

Firstborns tend to try to be “perfect” more often than later-borns. But kids without siblings, who are often treated like little adults, seem to have even more of this trait.

21 out of 23 of the first American astronauts were first born. All seven of the original Mercury astronauts were firstborns. Other famous firstborn trail-blazers: Winston Churchill, Bill Gates, JFK, and Oprah Winfrey.

It’s lonely at the top — or at least, at the beginning! A 2007 survey of corporate leaders found that 43% of CEOs were firstborns, 33% were middle children, and 23% were youngest children.

Even when parents try to be even-steven, it rarely works out that way. Kids born first get as much as 3,000 more hours of quality time with parents than younger siblings do at the same age. Parents spend about equal time with two or more kids. But there’s less total free time than there was when a firstborn passed through a given age.

It’s clear why birth order interests us so much. Most of us weren’t born as the only child in a family.

Older moms say they feel closest to their “babies” no matter what the family size or spacing between kids. In the same study, mothers said firstborns were the ones they’d turn to when facing personal problems or a crisis.